1. Field of the Invention
This invention relates generally to user interface devices. More particularly, the invention relates to interface devices for controlling temporal digital media including video, audio and animation.
2. Related Art
In current advanced computer-based, time-based media editing systems, inputs from a pair of devices are used to edit and control graphical objects contained within temporal digital media (e.g., audio, video and animation). Typically one of the devices is controlled by the dominant hand and the other by the non-dominant hand of the user. The device controlled by the non-dominant hand, the "manipulator" device, may be a six degree of freedom pointing device that is used to control the translation and rotation of a particular graphical object. The device controlled by the dominant hand is typically a locator device. This "pointing" device (e.g., mouse or stylus) is used to edit characteristics of the graphical object. In combination, this pair of devices allows a user to control and edit graphical objects appearing in a single graphical window for a specific time unit (e.g., frame).
As part of an overall editing process, the visually demanding task of manipulating objects in a single frame is magnified when working with a sequence of frames in video and animation. Moreover, the presentation of the frame is meaningful only in the context of a sequence of frames that portray virtual motion in video and animation. Accordingly, the editing of a graphical object, whose virtual movement spans multiple frames, represents an iterative process. This iterative process requires the editing of frames whose effect is continually scrutinized during video playback.
In known systems, the temporal control of the video playback is accomplished through a variety of devices and techniques. In one system, a "jog-shuttle" or "scrub wheel" is implemented as a dedicated, specialized transducer for issuing time commands. This device exists as a physical knob that controls video playback according to the knob's position along the one dimension of rotational freedom. In the combined editing and playback process, a user must relinquish control of one of the pointing devices to initiate and control the playback.
In other systems, graphical icons are used to represent the analogous VCR commands. These graphical icons not only require a break in the user's visual and mental concentration on the video playback but also consume valuable screen real estate. Still further some systems map the temporal controls to a set of function keys. This technique proves unsatisfactory because (1) the function mapping is not intuitively obvious to the user and (2) the binary nature (on/off) of the keys restricts playback options.
Finally, some systems implement Marking Menus. Marking Menus, which appear as a circular or "pie" menu centered around the current cursor position, are not visible until the mouse/pen dwells for a period of time. Whether visible or not, making an angular mark selects a pie wedge which then executes a command. This system is disadvantageous because it requires action by the dominant hand to activate a temporal control. The Marking Menu solution does not allow one to simultaneously edit graphical objects and issue transport commands.
Therefore, what is needed is an integrated mapping of temporal control features within the existing framework of time-based media editing systems that allows a user to efficiently edit graphical objects within the iterative process of video playback.